Method of forming cores for hollow castings



A. W. FINLAYSON.

IVIETHGD OF FORMING CORES FOR HOLLQW CASTINGS.

APPLICATION FILED SEPI 28, I9I 7.

Patented May 13, 1919.

utk/Lumix' m: Nmmls persas cov. Fnaforuruo wxsmucmwA u. c

ALEXANDER W. FINLAYSON, OF DETROIT, MICHIGAN.

METHOD OF FORMING GORES FOR HOLLOW CASTINGS.

Specification of Letters Patent.

Patented May 13, 1919.

Application led September 28, 1917. Serial No. 193,636.

To all 'whom t may concern:

Be it known that I, ALEXANDER W. FIN- LAYsoN, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Methods of Forming Cores for Hollow Castings, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to the art of forming cores for hollow castings, and it is the object of theinvention to obtain a method of quickly drying the cores without the necessity of placing the same in`an oven. To this end the invention comprises the novel method as hereinafter set forth.

In the drawings, I have illustrated my improved method as applied to the forming of a core for a radiator tube, an axial section through the core being shown.

The usual method of forming dry sand cores for hollow castings is to rst mold the core from moist material. After this material is sufficiently set, the core is placed in an oven and subjected to a baking process, which dries ofi' a portion of the moisture and renders the core fit for use in casting. The moisture is not, however, completely eliminated, and during the casting process the heat of the metal will generate vapors in the core which are sometimes conducted od through vent openings in the core. With the present invention I dispense' with the step of baking the core and proceed as follows:

A is the core, which in the specic con- Copies ot this patent may be obtained for struction illustrated is built about a central perforated tube B, on which is mounted a series of baffle plates C also embedded in the body. This core, while still in green state but sufficiently set to retain its shape, 1s coated with an inflammable Huid, such as gasolene, and is then ignited. The heat generated by the burning of this fluid is suflicient to dry the surface of the core, rendering the same in fit condition for contact with the molten metal.

The core formed as described can be manufactured without the long delay required for the baking process and in use is superior to the baked article. This is for the reason that the central portion, which still contains moisture, will impart greater strength to the structure, and during the casting operation, while under the heat of the molten metal, the vapor produced by this moisture will find exit through the perforated tube. This will avoid the filling of the metal with blowholes which might occur if no such vent were provided.

What I claim as my invention is:

The method of forming cores for hollow castings, comprising the molding of the core about a perforated centrally-arranged vent tube, coveringthe surface of the core with an inflammable fluid, and igniting the fluid to dry the surface portion of the core.

In testimony whereof I aX my signature.

ALEXANDER W. FINLAYSON.

five cents each, by addressing the "commissioner ot Patents.

Washington, D. G." 

